Lately there's been a large discussion about "gun control" in the United States. A lot of the movement towards removing guns or restricting their availability is because of one thing: Violent Crime.

This made me remember an article I read not too long ago on what the "Real Killer" is in America: Lead. More specifically on how leaded gasoline emissions in the 1940's - 1950's were the main culprit behind a rise in violent crime 20 years later, and their subsequent decline in the United States, Australia, Canada, Great Britain, Finland, France, Italy, New Zealand, West Germany, and the rest of the world when unleaded gasoline became the standard. It's a long article, but very well written. I'll quote the more important parts of the article, but in order to ascertain the whole concept you should read the full article.

The point is, if this article is correct, removing guns is useless because the real underlying factor isn't guns at all. It's the environment and the presence of lead. It's also scary to think that for all those decades as leaded gasoline emissions filled the air, it changed enough people that decades later we had a huge proliferation of violent crime. It's also scary to think that the properties of lead are lower IQ's, and that the population was subjected to this without knowledge.

Quote:

WHEN RUDY GIULIANI RAN FOR MAYOR of New York City in 1993, he campaigned on a platform of bringing down crime and making the city safe again. It was a comfortable position for a former federal prosecutor with a tough-guy image, but it was more than mere posturing. Since 1960, rape rates had nearly quadrupled, murder had quintupled, and robbery had grown fourteenfold. New Yorkers felt like they lived in a city under siege.

Throughout the campaign, Giuliani embraced a theory of crime fighting called "broken windows," popularized a decade earlier by James Q. Wilson and George L. Kelling in an influential article in The Atlantic. "If a window in a building is broken and is left unrepaired," they observed, "all the rest of the windows will soon be broken." So too, tolerance of small crimes would create a vicious cycle ending with entire neighborhoods turning into war zones. But if you cracked down on small crimes, bigger crimes would drop as well.

Giuliani won the election, and he made good on his crime-fighting promises by selecting Boston police chief Bill Bratton as the NYPD's new commissioner. The results were dramatic. In 1996, the New York Times reported that crime had plunged for the third straight year, the sharpest drop since the end of Prohibition. Since 1993, rape rates had dropped 17 percent, assault 27 percent, robbery 42 percent, and murder an astonishing 49 percent. Giuliani was on his way to becoming America's Mayor and Bratton was on the cover of Time. It was a remarkable public policy victory.

By 2010, violent crime rates in New York City had plunged 75 percent from their peak in the early '90s.

Quote:

All in all, it seemed to be a story with a happy ending, a triumph for Wilson and Kelling's theory and Giuliani and Bratton's practice. And yet, doubts remained. For one thing, violent crime actually peaked in New York City in 1990, four years before the Giuliani-Bratton era. By the time they took office, it had already dropped 12 percent.

Second, and far more puzzling, it's not just New York that has seen a big drop in crime. In city after city, violent crime peaked in the early '90s and then began a steady and spectacular decline. Washington, DC, didn't have either Giuliani or Bratton, but its violent crime rate has dropped 58 percent since its peak. Dallas' has fallen 70 percent. Newark: 74 percent. Los Angeles: 78 percent.

There must be more going on here than just a change in policing tactics in one city. But what?

Read the article for the rest. It goes on to discuss several theories that were written to address for the decrease in crime rates:

Economic Theory: That crime rates went down because the economy was booming in the 90's.

Crack Epidemic Theory: That there was a large crack epidemic in the 80's that flared down, and the subsequent switch of post-generations to choose marijuana over harsher drugs, leading to lower crime.

Demographic Theory: An increase in young male demographics leads to higher crime rates.

Prison Theory: The prison-construction boom leading to lower violent crime rates because criminals were incarcerated.

All of the above theories proved to be wrong, or inconclusive, or without proof. The rest of the article then focuses on the rejection the Lead Theory by law enforcement and other establishments because Law Enforcement tends to think from a "sociological" perspective rather than a scientific one, hence why they look in other areas for clues: Demographics, economics, drugs, etc.

I thinking this is junk Science, I hate when researcher try to draw causality from information like this. The scientific method say that you introduce something then see what happens then you remove it and see if everything returns to normal. Well they can not undo things and they can not say some other factor was not going on at the same time since the can not keep everyone isolated or in a test tube. We have more violence since we have more people walking around who can not tell right from wrong or could care less.

Also do you know in the 30's to 60's we use to keep nut case locked up away from the public and today they are free to walk and drive among us.

I thinking this is junk Science, I hate when researcher try to draw causality from information like this. The scientific method say that you introduce something then see what happens then you remove it and see if everything returns to normal. Well they can not undo things and they can not say some other factor was not going on at the same time since the can not keep everyone isolated or in a test tube. We have more violence since we have more people walking around who can not tell right from wrong or could care less.

Also do you know in the 30's to 60's we use to keep nut case locked up away from the public and today they are free to walk and drive among us.

But certainly when you look at data spanning different countries and they add up all congruently together, it's not as dissmable. While it's not verifiable to certainty, that's what most Scientific Theories are like. "Theories" backed by very probably data.

I'd imagine that we should see similar affects in China/India as they are over-crowded and demographically dense with a large exposure to industrial pollution (certainly lead). Let's see if their violent crime charts rise and fall the same way.